Genetics: From Genes to Genomes
6th Edition
ISBN: 9781259700903
Author: Leland Hartwell Dr., Michael L. Goldberg Professor Dr., Janice Fischer, Leroy Hood Dr.
Publisher: McGraw-Hill Education
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Chapter 21, Problem 20P
Tristan da Cunha is a group of small islands in the middle of the Atlantic Ocean. In 1814, a group of 15 British colonists founded a settlement on these islands. In 1885, 15 of the 19 males on the island were lost in a shipwreck. In the late 1960s, four cases of retinitis pigmentosa, which progressively leads to blindness, were found among the 240 descendants of these settlers remaining on the island. The frequency of retinitis pigmentosa in Britain is about 1 in 6000. Explain the high incidence of this disease on Tristan da Cunha relative to that seen in Britain.
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Tristan da Cunha is a group of small islands in themiddle of the Atlantic Ocean. In 1814, a group of 15British colonists founded a settlement on these islands.In 1885, 15 of the 19 males on the island were lost ina shipwreck. In the late 1960s, four cases of retinitispigmentosa, which progressively leads to blindness,were found among the 240 descendants of these settlers remaining on the island. The frequency of retinitis pigmentosa in Britain is about 1 in 6000. Explainthe high incidence of this disease on Tristan daCunha relative to that seen in Britain.
What do you notice is similar about the distribution of the HERC2 variant for blue eyes and the F374 allele for lighter skin pigmentation? Based on what you know about skin color and human variation, what evolutionary circumstances might have caused this distribution of the blue-eye variant?
Suppose we define the Alzheimer's disease phenotype as being diagnosed with the disease by age 75 years. In the human population, there are three alleles of the ApoE gene: e2, e3, e4. They form an allelic series such that:
70% of 75 year olds with the e4/e4 genotype have the Alzheimer's phenotype
60% of 75 year olds with the e3/e4 genotype have the Alzheimer's phenotype
40% of 75 year olds with the e3/e3 genotype have the Alzheimer's phenotype
30% of 75 year olds with the e2/e4 genotype have the Alzheimer's phenotype
10% of 75 year olds with the e2/e3 genotype have the Alzheimer's phenotype
If I have the e4/e4 genotype and my wife has the e2/e3 genotype, what is the probability that our child will have Alzheimer's by age 75. Explain your reasoning.
Chapter 21 Solutions
Genetics: From Genes to Genomes
Ch. 21 - Choose the best matching phrase in the right...Ch. 21 - When an allele is dominant, why does it not always...Ch. 21 - A population with an allele frequency p of 0.5 and...Ch. 21 - In a certain population of frogs, 120 are green,...Ch. 21 - Which of the following populations are at...Ch. 21 - A dominant mutation in Drosophila called Delta...Ch. 21 - A large, random mating population is started with...Ch. 21 - Prob. 8PCh. 21 - Alkaptonuria is a recessive autosomal genetic...Ch. 21 - Two hypothetical lizard populations found on...
Ch. 21 - It is the year 1998, and the men and women sailors...Ch. 21 - a. Alleles of genes on the X chromosome can also...Ch. 21 - In 1927, the ophthalmologist George Waaler tested...Ch. 21 - The equation p2 2pq q2> = 1 representing the...Ch. 21 - A gene has two alleles A frequency = p and a...Ch. 21 - Some people can taste the bitter compound...Ch. 21 - Androgenetic alopecia pattern baldness is a...Ch. 21 - The following figure shows the FBI-style analysis...Ch. 21 - Why is the elimination of a fully recessive...Ch. 21 - Tristan da Cunha is a group of small islands in...Ch. 21 - Small population size causes genetic drift because...Ch. 21 - Three basic predictions underlie genetic drift in...Ch. 21 - A mouse mutation with incomplete dominance t =...Ch. 21 - In Drosophila, the vestigial wings recessive...Ch. 21 - In a population of infinite size, three loci A, B,...Ch. 21 - You have identified an autosomal gene that...Ch. 21 - In Europe, the frequency of the CF allele causing...Ch. 21 - An allele of the G6PD gene acts in a recessive...Ch. 21 - Explain why evolutionary biologists monitor...Ch. 21 - Tiny foxes live on the Channel Islands off the...Ch. 21 - What is the most straightforward evidence at the...Ch. 21 - In March 2013, the American Journal of Human...Ch. 21 - If you go back 40 generations into your biological...Ch. 21 - In Fig. 21.17, to what part of the world does...Ch. 21 - Predict the DNA sequences at the four nodes...Ch. 21 - A cladogram not drawn to scale for the taxonomic...Ch. 21 - As noted in Fig. 21.22, humans now living in...Ch. 21 - As of this writing in 2016, no Neanderthal-derived...
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